Using EASI Sentinel-1 data¶
This notebook will demonstrate how to load and use Sentinel-1 data generated in EASI.
Adapted from https://github.com/csiro-easi/eocsi-hackathon-2022/blob/main/tutorials/SAR_data.ipynb
Introduction to Sentinel-1¶
Sentinel-1 carries a synthetic aperture radar (SAR) sensor, which can observe our planet even through cloud cover. Sentinel-1's SAR sensor is an active sensor; it emits light in the microwave range of the electormagnetic spectrum, and measures the amount that returns, known as backscatter. Smooth surfaces, like calm water, have very low backscatter - most of the light bounces away from the sensor (known as specular reflection). For rough surfaces, like dirt or vegetation, light is scattered in all directions, producing small backscatter signals (known as diffuse backscatter). Large, human-made structures, which feature both vertical and horizonal smooth surfaces, produce large backscatter signals (known as double bounce). As such, the intensity of Sentinel-1 backscatter can distinguish water from land, as shown in the image below:
In the image, the river appears dark (specular reflection), with the urban area appearing very bright (double bounce). For more information, see the article from GIS Geography on SAR.